1. Field of the Invention
The present invention generally relates to a current direction detection module and, more particularly, to a current direction detection module that detects directions of faulty currents in an electric power system.
2. Description of the Related Art
Power distribution networks of an electric power system are widely arranged all over a country for industry development. The electric power systems should be maintained in an efficient way to provide better service quality during the operation thereof. Thus, when an abnormality occurs in the electric power system, it is required to quickly find out the location of the problem and the root cause thereof. In light of this, human labors are conventionally used to repair the electric power system. However, this may not be an efficient way anymore as the modern electric power systems are arranged on a very wide range.
To solve the problem, many detection apparatuses have been developed to collect faulty information of an electric power system for centralized management. For instance, Taiwanese Publication Number 200837368 discloses a multi-ended fault location system, Taiwanese Publication Number 200933176 discloses a fault detection method of an electric power network and a system thereof, Taiwanese Patent Number 589651 discloses a protection relay, Taiwanese Patent Number 475991 discloses a fault point location system, Taiwanese Patent Number M379069 discloses a fault location device, and Taiwanese Patent Number M321170 discloses an automatic detection device for detecting faults of branched feed lines of a power distribution system. However, these conventional detection devices can only detect the occurrence of faulty currents in the electric power system rather than the directions of the faulty currents. As a result, the location of the problem can only be located by proceeding in a step-by-step manner starting from an area of the electric power system adjacent to the conventional detection devices. In a preferred case, if the directions of the faulty currents can be recognized, the problem will be quickly located.
Furthermore, another conventional detection device detects directions of faulty currents via a directional over current relay. Specifically, the conventional detection device detects the directions of the faulty currents by acquiring voltage and current phase information via at least a potential transformer and at least a current transformer. However, the potential transformer cannot be used on a single transmission path and it is required to detect phase voltages thereof (L and N phases). In addition, the potential transformer should have its primary side connected to circuits of the electric power system. Thus, usage of the potential transformer makes it more difficult to detect the directions of the faulty currents. Moreover, the method requires higher costs because both the potential transformer and current transformer are used.
Therefore, it is desired to improve the conventional detection devices.